IBM T400F FMR tape. See field microcode replacement tape, Gb. See gigabit GB. See gigabyte

Fibre Channel protocol. An evolving ANSI interconnection standard for high-speed data transfer among computers and storage devices defined by the Fibre Channel Protocol (FCP). At the physical level, data is transmitted serially over pairs of point-to-point links between FC ports. With appropriate components, data can be transferred at 100 MB/sec up over a distance of 10 km between FC ports. The ports can be configured in ring and switched interconnect topologies which allow each port to exchange data with any other port that is part of the same fabric.

Fibre Channel wrap test. A diagnostic that causes the Ultrium 2 Tape Drive to perform a check of the Fibre Channel circuitry from and to the drive’s Fibre Channel connector or the fiber cable.

field microcode replacement tape. A tape cartridge that contains new or revised firmware (microcode) for the Ultrium 2 Tape Drive.

file. A named set of records that are stored or processed as a unit.

filemark. Located on the magnetic tape within a tape cartridge, a recorded element that typically marks the organizational boundaries in a serial file structure (such as directory boundaries) and that is requested to be written or read by the server.

firmware. The proprietary code that is usually delivered as part of an operating system. Firmware is more efficient than software that is loaded from an alterable medium, and is more adaptable to change than pure hardware circuitry. An example of firmware is the Basic Input/Output System (BIOS) in read-only memory (ROM) on a PC motherboard.

FMR tape. See field microcode replacement tape.

foot. A unit of length comprising 12 inches.

G

Gb. See gigabit.

GB. See gigabyte.

Generation 1. The informal name for the IBM Ultrium Internal Tape Drive, which is the predecessor of the Ultrium 2 Tape Drive (Generation 2). The Generation 1 drive has a native storage capacity of up to 100 GB per cartridge and a native sustained data transfer rate of 15 MB per second.

Generation 2. The informal name for the Ultrium 2 Tape Drive, which is the second-generation version of the IBM Ultrium Internal Tape Drive (Generation 1). The Generation 2 drive has a native storage capacity of up to 200 GB per cartridge and a native sustained data transfer rate of 35 MB per second.

gigabit (Gb). 1 000 000 000 bits. 1 Gb equals 100 MB.

gigabyte (GB). 1 000 000 000 bytes.

ground. An object that makes an electrical connection with the earth.

H

hard addressing. Pertaining to the Fibre Channel drive (Model T400F), a method that identifies the drive’s LID and, consequently, its AL_PA (the AL_PA enables the drive to communicate with other devices).

hardware. The physical equipment or devices that form a computer.

head. See drive head.

Head Resistance Measurements test. Part of the Test Head diagnostic, a procedure that determines whether the tape drive’s head works correctly. The test measures the head’s ability to withstand cracks and other defects.

host. The controlling or highest-level system in a data communication configuration. Synonymous with server.

hot-pluggable.Pertaining to the Ultrium 2 Tape Drive, the ability to remove the drive from an enclosure while the enclosure is powered-on.

hub. A communications device to which nodes on a multi-point bus or loop are physically connected. Hubs are commonly used in Fibre Channel networks to improve the manageability of physical cables. They maintain the logical loop topology of the network of which they are a part, while creating a “hub and spoke” physical star layout. Unlike switches, hubs do not aggregate bandwidth. They typically support the addition or removal of nodes from the bus while it is operating.

I

IBM TotalStorage LTO Ultrium 2 Tape Drive. A data-storage device that controls the movement of the magnetic tape in an IBM LTO Ultrium Tape Cartridge. The drive houses the mechanism (drive head) that reads and writes data to the tape. The drive is the first of four drives planned for the Ultrium format. Its native data capacity is 100 GB per cartridge; with 2:1 compression, its capacity is up to 200 GB.

ID. Identifier.

in. See inch.

inch. A unit of length equal to 1/36 yard or 25.4 mm.

initiator. In SCSI terms, a SCSI device that requests an I/O process to be performed by another SCSI device (a target). In many cases, an initiator can also be a target.

108IBM TotalStorage LTO Ultrium 2 Tape Drive